Extrusion device for the manufacture of cable sheaths



w. HYPRATH 2,385,574 EX'I'RUSION DEVICES FOR THE MANUFACTURE OF CABLE SHEATHS Sept. 25, 1945.

Filed March 24, 1941 ATTORNEY I Patented Sept. 25,1945

EXTRUSIONDEVICE FOR THE MANUFAC- 'IIURE F CABLE BHEATHS Walter Hyprath, Berlin-Wilmersdorf, Germany;

vested in the Allen Property Custodian Application March 24, 1941, Serial No. 384,913

In Germany January 19, 1940 a cum ((1. 201-) This invention relates to extrusion devices, and more particularly to an extrusion block for applying aluminum sheaths to conductors of cables.

When applying metal sheaths to the conductors of cables, especially sheaths of metals having" a high fusing point, such as aluminum, the conductor of the cable is liable to sufler damage due to the eilect of the high extrusion temperature.-

It has already been proposed to protect the conductor by cooling it through the medium of a double-walled protective cylinder which is arranged in the extrusion block and traversed by a cooling agent. However, this protectivecylinder, in prior structures, is tightly fitted in a bore provided in the extrusion block. The cooling agent iiowing through the hollow jacket of the protective cylinder therefore exerts the desirable cooling action on the conductor of the cable,but

at the same time'an undesirable cooling action on the extrusion block thereby cooling the filling material, and thus preventing the production of a satisfactory cable sheath.

The present invention provides aheat insulating layer between the protective cylinder and the bore in the extrusion block through which the protective cylinder extends, thereby preventing the detrimental cooling oi the extrusion block by the cooling agent flowing through the protective cylinder.

The accompanying drawing shows ane'mbodiment of the invention in diagrammatic form, Fig. 1 illustrating a vertical longitudinal sectional view of the extrusion block; Fig. 2 representing an enlarged vertical sectional view of the extrusion block, partly broken away; and Figs. 3, 4 and 5 showlngsectional views taken on the lines III-III of Fig. 1' and IV-IV of Fig. 2.

The extrusion block I shown in Fig. 1 is particularly provided for applying an aluminum sheath to the conductor of a cable. It is threade'dly connected with the core holder 2, to which is secured the 'diecore l and is also threadedly I connected with thenut 4, l holder 2 is disposed thedouble-walled metal pro-- In the bore of the core tective cylinder 8 for. protecting and cooling the conductor of a cable (not shown). 'I'hiscylinderis provided with an inlet I and an outlet I for the cooling water. The cooling water flows through the hollow jacket I around the guidemember II.

The outer Jacket surface ii of the protective cylinder is spaced from the inner wall of the bore 12 of the coreholder 2 by an annular. space ll communicating with the outside atmosphere. A detrimental cooling of the core'holder 2 and of the extrusion block I caused by the cool a ent flowing through the protective cylinder 6 is pre-- vented by the air contained in the space It. The I protective cylinder is secured in concentric position in the bore I! of the core holder 2 by spacer lugs 14 which may be made of a poorheat-conducting material, such as steatite, so as to prevent any appreciable dissipation of heat from the extrusion block to the protective cylinder.

As will be seen from Fig. 2, the protective cyllinder has at its inner end a. truncated conical portion II. The outer jaclget surface of this conical portion is separated from the inner conical j metal surface ii of the core 3 by an annular space I! which is in communication with the intermediate space is and which contains an air layer serving to insulate the heat. The cooling agent flowing through theprotective cylinder 8 is thus prevented from exerting a cooling action on the core 3.

The cable issuing from the die I and provided with an aluminum sheath is cooled by a sprayingdevice it. This spraying device comprises a cylinderv is through which passes the cable and in whose upper'part is arranged a tubular section I. so as to form a distributing chamber 2| for the cooling water. The cooling liquid, flows through the inlet 22 into-the chamber 21 and i8 squirted out through the perforations" to cool the cable sheath. At the outer end ofthecylinder II is provided an inclined portion 24 for discollectcharging the used cooling water into the ingtankil (Fig. 1); Y

The portion of the cylinder is projecting into the bore is surrounded by a protective cylinder 2|. Between the cylinders l0 and II is provided. an annular space 21. The cylinders II and I! are. held in the concentric position with respect. to each other by means of lugs 28 provided on the cooling cylinder is. The outer Jacketsurface 2! of the protective cylinder It is spaced from the bore 30 of the put 4 by an annular-space II communicating with the outside atmosphere and containing an air layer serving to insulate the heat. On the protective cylinder 2' are provided I conical spacers 32 consisting of steatite or any other poor heat conducting material and which maintain the" protective cylinder II in. a concentric position with respect to the bore ll. I

At the left-hand end, the protective cylinder 31- is'bent at right angles to form a flange 88 which has a relatively large opening 34. Betwe'en the flange l8 and the die I there'is a space "II communicating with. the space II and serving to' insulate the heat. An interchangeably arranged cap ll fits very closely to the flange I8 and has.

an opening 31 whose diameter is slightly greater than the outer diameter of the aluminum sheath applied to the conductor of the cable. The funnel-shaped enlargement 38 provided at the outer end of the protective cylinder 26 discharges the cooling water used into the collecting tank 25 The protective cylinder 26 (Fig. 2) protects the nut I against the cooling water squirted out from o the sprayer device iii. The water squirted onto the aluminum sheath of the cable through the perforations 2a is collected at the bottom of the cooling cylinder l9 At the discharge end '24 the claim 1, wherein said holder is removably attached to said extrusion block at one end thereof, and wherein said protective cylinder is removably disposed within said holder.

cooling water. flows in part into the collecting tank l5. The other portion of the cooling water flows.

over-the inner edge of the tube l9 to the bottom of the space 21 and is then discharged at the funnel-shaped end as into the tank 25. The protective cap 36 prevents the cooling water flowing over the inner edge oi the cylinder it from bein splashed ontothe die 5. i

In case an aluminum sheath of'a greater or smaller outer diameter should be applied to thecable, the cap 35 is replaced by another cap having a suitable bore adapted to the outer diameter of the aluminum sheath.

The funnel-shaped enlargement 38 prevents a splashing of the codling water flowing from the space 21 onto the nut What is claimed is: I 1. Apparatus for applyingmetal sheathing to a cable conductor comprising an extrusion block having an axially extending channel and a radial- 4. The structure and combination defined in claim 1, together with lugsmade ofpoor heat conducting material disposed between said protective cylinder and the inside wall of said holder for maintaining said cylinder in concentricposition within said holder and spaced therefrom. I

.5. The structure and combination defined in claim 1, together with means for defining pass.

sageways for directing a cooling medium through the walls of said protective cylinder.

6. Apparatus for applying metal sheathing to" a cable conductor'comprising an extrusion block having an axially extending channel and a radially extending opening communicating therewith j for supplying metal in heated plastic condition thereto, a die core disposed in said channel ad- :Iacent said opening for receiving said conductor which (is fed into said block from one side thereof for the application of said sheathing within said opening, a tubular holder mounted in the 1y extending opening communicating therewith for supplying metal in heated plastic condition thereto, a die core disposed in said channel ad iacent said opening for receiving said conductor which is fed into said block from one side thereof a for the application of said sheathing within said channel of said block, said die core being secured on the end of said holder adjacent said openin and having a converging bore, and a tubular pro-.

tective cylinder disposed within said holder substantially throughout the entire length thereof.

. andcomprising an inner tubular jacket and an opening, a tubular holder mounted in the channel of said block, said die core being secured on the end of said holder adjacent said openingand having a converging bore, and a protective cylinder having an axially extending opening'therethrough and a truncated conical portion at one end, said cylinder being disposed within said holder substantiaily throughout the entire length thereof ical portion extending into said converging bore,

and annularly spaced from the die core for protecting said conductor within said block before it is received by said die 'core, the annular space outer tubular' acket about said inner tubular jacket, annularly spaced from said holder and from said inner tubular jacket, and a truncated conical end connecting said jackets and extend-' ing into said converging bore, andannularly '7 but annularly spaced therefrom.'its truncated conspaced from the die core for protecting said con -ductor within said block before it is received by said die core, the annular space between the die .core and the conical end communicating with the annular spa'cebetween the holder and the outer jacket, andthe latter space communicating with the atmosphere.

I WALTER HYPRATH. 

